/Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityManager.h
Changes the components that exist on an entity to a new mask
void ChangeEntityType ( [FMovieSceneEntityID](API\Runtime\MovieScene\EntitySystem\FMovieSceneEntityID) InEntity, const [FComponentMask](API\Runtime\MovieScene\EntitySystem\FComponentMask) & InNewMask )